Bellows



Feb. 23, 1960 E. R. THoMPsoN, SR 2,925,829

BELLOWS Filed Sept. 11, 1958 INVENTOR Ell/'ot Thompson, 5r. BY M4'ATTORNEYS Unit-Cd States Patent fr i nELLows Elliot R. Thompson, Sr.,Windsor, Conn., assignor to The j lllelfab Corporation, Agawam, Mass., acorporation ol?Y "yvoridaf'f4v t d f .f AApil-[cation september 11,195s, serinNo. 160,412

j sjclaims.' (ci. 137-796) u This Yinvention.relates` to'bellows andrelates more par- Nnce . 2 ment. This provides a very strong connectionbetween the diaphragm elements. When the internal and external pressureson the bellows are approximately equal the outer marginal portions ofthe elements 11 and 12 of each ilange adjacent the weld whichinterconnects them,

tend to be separated to approximately the extent indicated in Fig. 3,while the inner margins adjacent the corresponding weld tend to beseparated to the extent indicated in-Fig. 4. However, owing to thisconstruction, when there `is an increase, especially a rapid increase,in the internal pressure in the bellows the lastticularly tohighpressure, welded metal bellows of the i with reference Vto theinternal pressure thereon.

ters ofthe bellows wouldjchange and, therefore, the results` effected bythebellow'slwould also change. This was found to be a serious ila'wfandresulted, for example, in incorrect instrument readings. It was foundthat if the effective diameter of a bellows increased an instrumentreading would be inaccurate and would be too high, while 4 if theeffective diameter was decreased the measured reading would, again, beincorrect but ,would be top low. Usually Vit is desirable tomaintain Yalinear relationship between the pressures which are to be measureduby` abellowsA and the instrument reading which is effected bythe operation ofthebellows. The object of the invention is to provide a` welded metalbellows of thewnesting type, which strongly and eiectively resistsforces tending to change its elective diameter.

n `In, the drawing:

v Fig. 1 is an end view of `a bellows embodying the ini vention;

Fig.I 2 is enlarged sectional view taken on line 2-2 er1-fig.` 1;i Y

I ,Fig. :3- isla; fragmentary longitudinal sectional view of aconventional bellows showing the operation of the bellows`v undercertain pressure conditions; and

Fig 4 is a view similar to Fig. 3 showing the operation of .theconventional bellows under other pressure conditions.- ,j Y d or thepurpose of simplifying the description and for a ,better understandingof the invention and the problemswhich 'were encountered, theconventional nesting bellows (see Figs. 3 and L4) will be describedfirst.` This bellows, ,which is shown only by way of example, `has onlytwo flanges but it ,will be understood that the bellowsy may haveanydesired number of anges, the ilanges being indicatedat 10. Each ilange`10 is constructed from two diaphragm elements 11 and 12 which are soshaped that` they tend to nest with one another when thebellows tends tocollapse. For this purpose the diaphragm elements, which may beV formedof ilex-V ible annular plate members, are undulated or corrugated, theundulations or corrugations of the diaphragm elementll corresponding tothe corrugations of the diaphragm .element 12. To form the ilanges 10and mentioned marginal portions of the diaphragm elements tendntosqueeze together in the manner shown in Fig. 3, thereby changing theeffective diameter of the bellows, particularly with reference toexternal pressures on the bellows. -Conversely, when there is anincrease in the externalpressure applied to the bellows the outermarginal portions of the diaphragm elements tend to squeeze together inthe manner indicated in Fig. 4 thereby changing the effective diameterof the bellows, particularly changes in the elfective area ofthe bellowsthrow out instruments, for example, which may be operated by thebellows. It is manifest that this may be extremely dangerous in suchapplications as aircraft, for example.

` To overcome this problem or tend to resolve it very effectively, `Ihave devised the bellows shown in Figs. 1 andf 2 of the drawings by wayof example. In the illustrated form the bellows is shown per se andconsists of three anges Y13. However, it will be understood that thebellows', may be operatively associated with any suitable instrument-ormechanism and may have any number of flanges. Each flange 13 includes adiaphragm element 14` and a diaphragm element 15. The diaphragm elements14 and 15 are formed from flexible annular plates of metal, each havinga plurality of reversely arranged curves therein forming rather sharpannular corrugations. The corrugations of the element 14 are indicatedat 16, while the corrugations of the element, 15 arelindicated at 17.Throughout the greater.

- part thereof the corrugations 16 correspond to the corrugations, 17*so` that the diaphragm elements 14 and 1S have, in general, `a nestingrelationship to one another. l

1The diaphragm' element 14 has a flat inner marginal portion, as at 18,and a at outer marginal portion, as at 19. The diaphragm element 15 hasa at inner marginal portion, as at 20, which is of less ydepth than themarginal portion 18, and the element 15 has aliat outer marginalportion, as at 21, of less depth than the marginal portion 19. To formthe bellows sucto connectthe flanges to one another the` diaphragm ele-I ments are welded together alternately at their inner cessive diaphragmelements are welded together alternately at their inner and outermargins, preferably by arc welding the material, so that the material ofone diaphragm element fuses with the material of the adjoining diaphragmelement to form a very strong joint.

This. type of joint is far superior to a joint which includes spacerelements between the respective diaphragm elements and welded thereto.Furthermore, the omission of spacers between the respective diaphragmelements tends, to reduce the bulk of the bellows. As shown in Fig. 2,the ydiaphragm elements 14 and 15 have substantiallyV the same diametricdimensions and the outer marginal portions of the elements 14 areapproximately flush withthe corresponding diaphragm elements 15, whilethe inner marginal portions of the diaphragm elements V14 aresubstantially ush with the inner marginal portions of the correspondingdiaphragm elements 15.

Totend to prevent the outer marginal portion of each bellows ange 13from being collapsed by external pressure, that is the portion of theflange directly inward and adjacentV the outer weld, the diaphragmelements 14 and Patented Feb. `23, 1960.

The t 15'of-the llange areprovided in this area with noncony only by wayof example in the drawing,Y the nonconformingvv surface l'4ais providedbyy aninward `straight extension oftheatvmarginalportion '-19 oftheele'ment 14 which is welded to the corresponding-portion of.the-element-15. The nonconforming surface 15a is formedby acontinuation or extension of the outermost V4corrugation ofthe element-15 a distance past thecorresponding corrugation of the element 414, asshown in Fig. 2. As shown in the last-mentioned View, the curvedortapered surface 15a terminates at'its outer extremity at a rather sharpinclination to the straight extension'1484 ofthe Inarginal portion 19.These nonconforming surfaces ofthe diaphragm elements veryeectively tendto prevent occlusion in the bellowsin thisfreg'ionwhen-there is anexternal force applied to the bellows tending to presspthe diaphragmelements together in thi's'region. The curvature of the outermostcorrugation ofthe diaphragm element 15 also vfacilitates resistancel tothis compressive force.

The arrangement of the adjoining inner marginal portions of thediaphragm elements 14 and 15is substantially identical to thearrangement of the outer marginal portions to strongly resist completecollapse of the bellows inthis region occasioned bypressure within thebellows. To this end each diaphragm element 15 is provided with anonconforming externally curved surface 15b similar to the curvedsurface 15a described above,` while `each diaphragm element 14 is in thecorresponding region provided with a substantially -at external surface14b formed as an inward extension of the flat marginal portion 18 andsimilar to the surface 14)a described above; The inner and outer pairsof nonconforming surfaces may be easily formed by providing thediaphragm element 15 with ilat inner and outer marginal portions 'ofless depth than the inner and outer marginal portions of the diaphragmelement 14, and by extending the corrugationof the dia While only oneform of the bellows has been'illustrated l in the drawing and describedabove, it will be apparent to those versed in the art that the bellowsmay take other forms and is susceptible of various changes in detailsWithout departing from the principles of the invention and the scope ofthe 'appended claims.

What i claim is:

l. A nesting bellows comprising a plurality of pairs o f flexibleannular diaphragm elements of metalarranged in opposing relationship,each element having Substantially flat inner and outer margins andhaving therebetween a radially central portion of sharply corrugatedform, one element of each pair having the 'substantially' Y gins ofeachipairof diaphragm elements Vbeing fused in substantially iiushrelation to the inner margins ofthe respective diaphragm elements of theadjoining pairs, whereby the corrugations of said ones of the elementsoverlap said substantially flat inner and outer margins of said othersof the elements and provide nonconforming surfaces to resist collapseofthe` diaphragm elements in flat margins thereof of shorter radialdimensions than the these regions. s

2. A nesting bellowsconiprising a plurality of flanges inadjoiningrelation-to onel another and each formed by a pair of `flexibleannular-diaphragm elements of metal arranged in opposing relationship,the outer .edges of the diaphragm elements of each pair being fusedtogether and the inner'edges of the diaphragm elements being fused tothe inner'edges -of the respective diaphragm elements of the adjoiningflanges, the diaphragm elements of each pair having radially centralportions of undulated form and of substantial area, the undulations inthe central portion of one velement of each 'pair-'substantiallycorresponding 'to the lundulations inI theV central portionY of theother element of the pair so th'at'gthe diaphragm elements may tend tovnest withone another inthis region, the diaphragrnselernents ofeach pair'having 1relatively narrow nonconforming portions Iofanriuvlarformradially outwardly ofsaid central portions adjacent the respective fusedouter edges and extending to said central portions in opposingrelationto one another tending to resistthe collapse of Oneelement of apair of diaphragrns with the other, one nonconforming portion beingformed by an extension of `the undulatio'n of the corresponding'elementand the other nonconforniing -p'ortion'being formed by a at partdisposed in a planefsubstantially at right angles to the axis ofthebellows.

` 3`. A nesting'be'llows comprising a vplurality of flanges in'adjoining relation toron'e another and each formed by a pair offlexible ann'ularfdiaphragm elements of metal arranged in opposingrelationship, Athe outeredges yof Vthe diaphragm'elenrents ofeach'lpairfbeing'fused together and the inner edges of the "diaphragmelements being fused to the inner edgesof the :respective'diaphragmvelements of the adjoining flanges, the diaphragm elements of each pairhavingradiallycentral portionsv of undulated form and of substantialarea, thefundulations inv the central portion of one element 'of'eachpair Isubstantially corresponding tothe undulations in the *centralportion of the other elementofthe pairso `that the diaphragm elementsmay tend to nest with one another in this region, the diaphragm elementsof each pai'r'ihavin'g Jrelatively narrow nonconforming portions ofannular form radially inwardly of said central p ortions andadjacent'the :respective inner edges `and extendingto Ysaid centralportions, to resist collapse of one element of a `pair ofy diaphragrnswith the adjoining element of the next `pair,""'the nonconformingportion of said one of the elements 4being formed by lan extension ofthe undulations therein, and :the nonconforming portion of said`adjoining element being formed by a susbstantially flat part disposedin a plane substantially at right langles to the axis of the bellows.

4. A nesting bellows comprising a plurality of flanges in adjoiningrelationto -one another and each formed by a pair of ilexible vannulardiaphragm `elements of metal arranged in opposing relationship, the'outer edges of the diaphragm elements of each pair being fused togetherland the inner edgesof the diaphragm elements ibeing fused to the inneredges of the respective diaphragm elements of the adjoining anges, thediaphragmielements of each pair having radially central portions ofundulated form andof substantial area, theundulations in the centrallportionof one element 'of `each pair Isubstantially corresponding tothefundulations -in the central portion of the other element ofthe-pairso that the diaphragm elements may ltend to nest withone-another inthis region,

thediaphragm elements having relatively `narrow -nonconforming portionso'ffannular form radially inwardly and'outwardly of'A said`centralportions and adjacent the respective inner and outer edges andextending to said central portions, to resist collapse of one element ofa pair of diaphragms with the other and the collapse of one element of apair with the adjoining element of the next pair, said one of theelements having the inner and outer nonconforming portions thereofformed by an extensiony of the undulations therein, and said adjoiningelement and said other element having their inner and outernonconforming portions formed by substantially flat parts disposed inplanes substantially Iat right angles to the axis of the bellows.

5. A nesting bellows comprising a plurality of flanges in adjoiningrelation to one another and each formed by a pair of flexible annulardiaphragm elements of metal arranged in opposing relationship, the outeredges of the diaphragm elements of each pair being fused together andthe inner edges of the diaphragm elements beingfused to the inner edgesof the respective diaphragm elements of the adjoining ilanges, thediaphragm elements of each pair having radially central portions4 ofundulated form and of substantial area, the undulations in the centralportion of one element of each pair substantially corresponding to theundulations in the central portion of the other element of the pair sothat the diaphragm elements may tend to nest with one another in thisregion, the diaphragm elements having relatively narrow nonconforrningportions of annular form radially inwardly and outwardly of said centralportions and adjacent the respective inner and outer edges and extendingto said central portions, to resist collapse of one element of a pair ofdiaphragms with the other and the collapse of one element of a pair withthe adjoining element of the next pair, said one of the elements havingthe inner and outer nonconforming portions thereof formed by concavesurfaces constituted by continuations of the undulations in the element,and the nonconforming portions of said other element and said adjoiningelement being formed by substantially at parts disposed in planessubstantially at right angles to the axis of the bellows.

6. A nesting bellows comprising a plurality of pairs of flexible annulardiaphragm elements of metal arranged in opposing relationship, eachelement having substantially at inner and outer margins and havingtherebetween a radially central portion of corrugated form, one elementof each pair having the substantially flat margins thereof of shorterradial dimensions than the substantially fiat margins of the otherelement, said ones of the diaphragm elements being arranged alternatelywith said others of the elements in the bellows, the corrugated portionsof the elements substantially corresponding with one another in the areawhere the corrugations are in opposing relationship so that the elementsmay tend to nest in this area, said substantially at outer margins ofeach pair of diaphragm elements being fused together and saidsubstantially flat inner margins of each pair of diaphragm elementsbeing fused to the inner margins of the respective diaphragm elements ofthe adjoining pairs, whereby the oorrugations of said ones of theelements overlap said substantially flat inner and outer margins of saidothers of the elements and provide nonconforming surfaces to resistcollapse of the diaphragm elements in these regions.

References Cited in the le of this patent UNITED STATES PATENTS 966,790Bristol Aug. 9, 1910 1,454,459 Stalker et al. May 8, 1923 1,786,506 RayDec. 30, 1930 2,303,911 Clark Dec. 1, 1942 2,729,243 Senn Ian. 3, 1956FOREIGN PATENTS 387,902 Great Britain Feb. 16, 1933

